/**
 * Moondance UML modeling tool
 * 
 * This program is free software; you can redistribute it and
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 3
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

package ro.pub.cs.se.moondance.directedit;

import org.eclipse.jface.viewers.ICellEditorValidator;

import ro.pub.cs.se.moondance.model.VisibilityType;

/**
 * ICellValidator to validate direct edit values in the class label.
 * Collaborates with an instance of ValidationMessageHandler
 */
public class ClassNameCellEditorValidator implements ICellEditorValidator {

	private ValidationMessageHandler handler;

	/**
	 * @param validationMessageHandler
	 *            the validation message handler to pass error information to
	 */
	public ClassNameCellEditorValidator(
			ValidationMessageHandler validationMessageHandler) {
		this.handler = validationMessageHandler;
	}

	/**
	 * @param validation
	 *            of class name
	 * @return the error message if an error has occurred, otherwise null
	 */
	// visibility <<abstract>> name
	public String isValid(Object value) {
		String name = (String) value;

		if (name.length() == 0) {
			String text = "Class definition should include at least a name. The valid format is: visibility <<abstract>> name.";
			return setMessageText(text);
		}

		String[] result = name.split("\\s");

		switch (result.length) {
		case 1: // name | pattern | visibility
			if (result[0].startsWith("<<") && result[0].endsWith(">>")) {// pattern
				// name
				String pattern = result[0].substring(2, result[0].length() - 2);
				if (!pattern.equals("abstract")) {
					String text = "Invalid pattern. The valid format is: visibility <<abstract>> name.";
					return setMessageText(text);
				}
			}
			break;
		case 2: // visibility name || pattern name || visibility pattern
			if (result[0].startsWith("<<") && result[0].endsWith(">>")) {// pattern
																			// name
				// name
				String pattern = result[0].substring(2, result[0].length() - 2);
				if (!pattern.equals("abstract")) {
					String text = "Invalid pattern. The valid format is: visibility <<abstract>> name.";
					return setMessageText(text);
				}
				if (ForbiddenIdentifierNames.contains(result[1])) {
					String text = "Class name is an invalid identifier. Do not use java keywords as class names.";
					return setMessageText(text);
				}
			} else {// visibility name || visibility pattern
				if (!VisibilityType.contains(result[0])) {// visibility
					String text = "Invalid visibility type. Permissible types are: "
							+ VisibilityType.getTypes();
					return setMessageText(text);
				}
				if (result[1].startsWith("<<") && result[1].endsWith(">>")) {// pattern
					String pattern = result[1].substring(2,
							result[1].length() - 2);
					if (!pattern.equals("abstract")) {
						String text = "Invalid pattern. The valid format is: visibility <<abstract>> name.";
						return setMessageText(text);
					}
				} else {
					if (ForbiddenIdentifierNames.contains(result[1])) {// name
						String text = "Class name is an invalid identifier. Do not use java keywords as class names.";
						return setMessageText(text);
					}
				}
			}
			break;
		case 3: // visibility pattern name
			if (!VisibilityType.contains(result[0])) {
				String text = "Invalid visibility type. Permissible types are: "
						+ VisibilityType.getTypes();
				return setMessageText(text);
			}
			String pattern = result[1].substring(2, result[1].length() - 2);
			if (!pattern.equals("abstract")) {
				String text = "Invalid pattern. The valid format is: visibility <<abstract>> name.";
				return setMessageText(text);
			}
			if (ForbiddenIdentifierNames.contains(result[2])) {
				String text = "Class name is an invalid identifier. Do not use java keywords as class names.";
				return setMessageText(text);
			}
			break;
		}

		unsetMessageText();
		return null;

	}

	private String unsetMessageText() {
		handler.reset();
		return null;
	}

	private String setMessageText(String text) {
		handler.setMessageText(text);
		return text;
	}

}